| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 060464000 | Of motive fluid transfer between a reservoir and a recirculating path of a pump motor loop | 23 |
| 20080289326 | Pump Unit - The present invention provides a pump unit including at least one hydraulic pump with inlet and outlet ports, a pump case for accommodating the hydraulic pump having an opening through which the hydraulic pump is insertable, and a lid, called a center section, closing the pump case. The center section forms a pair of inlet/outlet passages communicating an end with the inlet and outlet ports of the hydraulic pump and an end opening through a pump case abutting surface of the center section, and a first charging passage by which hydraulic fluid is fed through the pump case abutting surface of the center section. At least one of the pump case and the center section communicates the first charging passage with the pair of inlet/outlet passages via a first hydraulic fluid feeding valve preventing the reverse flow into said first charging passage. | 11-27-2008 |
| 20090064675 | Flushing system having a single charge relief valve - A flushing system for a transmission is disclosed. The system has a first pump and a first actuator connected to the first pump to form a first loop. The system also has a second pump and a second actuator connected to the second pump to form a second loop. The system further has a charge pump configured to replenish the first and second loops. The system also has a single charge relief valve situated to receive fluid from the first pump, the second pump, and the charge pump. | 03-12-2009 |
| 20100170240 | HYDRAULIC RESERVOIR PRESSURE RELIEF MECHANISM - An exemplary hydraulic reservoir includes a reservoir tank having an interior cavity for retaining a fluid and an aperture fluidly connecting the interior cavity to an exterior region of the reservoir. A cover selectively engages the reservoir tank, and is movable between an open position, wherein the fluid path through the aperture in the reservoir tank is at least partially open, and a closed position, wherein the fluid path through the aperture is substantially closed. The hydraulic reservoir further includes a pressure relief mechanism having at least one pressure responsive fastener for releasably connecting the cover to the reservoir tank. The at least one pressure responsive fastener includes a fastener fixed for concurrent movement with one of the cover and the reservoir tank, and a biasing member operably connecting the fastener to whichever of the cover and reservoir tank is not fixed for concurrent movement with the fastener. | 07-08-2010 |
| 20110088385 | Fluid pressure actuator unit - A fluid pressure cylinder ( | 04-21-2011 |
| 20110277459 | Hydrostatic Drive - A hydrostatic drive, in particular a fan drive, with a variable displacement pump is configured to drive at least one hydraulic motor. The variable displacement pump is activated via a pressure regulating valve and a following directional valve predetermining the feed direction, via which valves the control spaces of an actuating cylinder can be acted upon with a control pressure difference. The variable displacement pump is prestressed into a basic position in which the feed volume flow is maximum. | 11-17-2011 |
| 20110302915 | HYDRAULIC PRESSURE CONTROL DEVICE - A hydraulic pressure control device including a valve for generating a circulating pressure to a hydraulic power transmission chamber in which power is transmitted between an input- and output side of a hydraulic power transmission element via hydraulic oil; and a valve for generating a lock-up pressure supplied to a lock-up chamber that faces the hydraulic power transmission chamber with a lock-up piston included in a lock-up clutch interposed therebetween. The hydraulic pressure control device controls the hydraulic pressures in the hydraulic power transmission chamber and in the lock-up chamber; and the circulating pressure valve has a spool to which the circulating pressure is applied as a feedback pressure and another hydraulic pressure is applied when the lock-up clutch is engaged/disengaged, and a spring urges the spool, and sets the circulating pressure to a constant first pressure when the lock-up clutch is disengaged and to a constant second different pressure when the lock-up clutch is engaged, depending on forces to the spool by the feedback pressure and on the spring. | 12-15-2011 |
| 20120060487 | WORKING MACHINE - In the working machine, first and second pilot flow paths are directly or indirectly connected to to a tank flow path ( | 03-15-2012 |
| 20130047599 | METERLESS HYDRAULIC SYSTEM HAVING LOAD-HOLDING BYPASS - A hydraulic system is disclosed. The hydraulic system may have a pump, a hydraulic actuator, and first and second passages fluidly connecting the pump to the hydraulic actuator in a closed-loop. The hydraulic system may also have a control valve, and a load-holding valve configured to selectively lock movement of the hydraulic actuator. The load-holding valve may include a valve block at least partially defining a pump passage, an actuator passage, a control passage, a restricted passage connecting the actuator passage and the control passage, and a bypass passage connecting the actuator passage and the control passage. The load-holding valve may also include a valve element movable between a first position at which flow between the pump and the hydraulic actuator is blocked, and a second position at which fluid is allowed to flow between the pump and the hydraulic actuator, the valve element being spring-biased toward the first position. | 02-28-2013 |
| 20140331664 | SLEWING TYPE WORKING MACHINE - Provided is a slewing-type working machine capable of reducing back pressure generated during slewing. The slewing-type working machine includes: a base carrier; an upper slewing body; a hydraulic motor | 11-13-2014 |
| 20140345267 | FLUID VALVE ARRANGEMENT COMPRISING A BISTABLE FLUID VALVE - The invention relates to a fluid valve arrangement having a bistable fluid valve for at least one fluid line with a valve body which can be moved into two positions for two switching states, a pressure pulse generator being provided for valve switchover in the feed line for switching over a feed line and a return line between two flow lines, and the fluid valve comprising a reversing unit which has two chambers which are separated from one another by a bistable surface element, the two chambers being connected to the two flow lines and the bistable surface element being operatively coupled to the valve body in order to actuate it. As a result, a bistable fluid valve is provided which can be reversed by way of pressure pulses or pressure flanks and otherwise has no energy requirement. | 11-27-2014 |
| 20140345268 | TRAVEL CONTROL SYSTEM FOR CONSTRUCTION MACHINERY - A travel control system is disclosed for preventing off-course travel of equipment due to the overloading of a working piece such as a boom during a complex operation involving vehicle travel and simultaneous driving of the working piece. The travel control system according to the present invention comprises: a left-side travel motor and first working piece coupled to a first hydraulic pump; a plurality of change-over valves for respectively controlling operating fluid supplied from the first hydraulic pump to the left-side travel motor and first working piece; a right-side travel motor and second working piece coupled to a second hydraulic pump; a plurality of change-over valves for controlling operating fluid supplied from the second hydraulic pump to the right-side travel motor and second working piece; a straight-ahead travel valve for supplying the operating fluid of the first hydraulic pump to the left-side and right-side travel motors and supplying the operating fluid of the second hydraulic pump to the first and second working pieces; and a control valve for blocking the supply of operating fluid from the second hydraulic pump, via the straight-ahead travel valve, to the left-side travel motor and right-side travel motor during complex operation involving travel and the working piece. | 11-27-2014 |
| 20140360174 | BOOM CYLINDER CONTROL CIRCUIT FOR CONSTRUCTION MACHINE - The present disclosure relates to a boom cylinder control circuit for a construction machine, and includes: a boom cylinder which has an ascending-side chamber and a descending-side chamber; a boom control unit which provides a working fluid to the boom cylinder; a boom operation part which is operated to drive the boom cylinder by providing a pilot working fluid to the boom control unit; a first floating valve which allows the descending-side chamber and the ascending-side chamber to selectively communicate with or be shut off from a first drain line; a second floating valve which is additionally provided in a flow path between the descending-side chamber, which is connected with the first drain line via the first floating valve, and the first drain line, allows the descending-side chamber to communicate with the first drain line, or shut off discharge of the working fluid from the descending-side chamber to the first drain line, and allows of a reverse flow; and a floating selection operation part which provides an operation signal so that the first floating valve and the second floating valve are switched in a direction in which the first floating valve and the second floating valve are communicated or shut off. | 12-11-2014 |
| 20140366520 | Fluid Controller with Load Sense and Flow Amplification - A fluid controller includes a valve housing having an inlet port, a return port, first and second control ports and a load sense port. The fluid controller further includes a fluid meter in selective fluid communication with the valve housing and a valve assembly adapted to provide selective fluid communication between the valve housing and the fluid meter. The valve housing includes a main flow path and a load sense flow path. The main flow path is adapted to provide selective fluid communication between the inlet port and the first control port. Fluid in the main flow path passes through the fluid meter. The load sense path is adapted to provide selective fluid communication between the load sense port and the main flow path. The load sense flow path includes a variable load sense orifice that substantially closes prior to a maximum rotational displacement of the valve assembly. | 12-18-2014 |
| 20140366521 | HYDRAULIC DRIVE SYSTEM - A hydraulic drive system includes a pump, a steering actuator, a loading/unloading apparatus actuator, a drive device, a relief valve, and an input unit. The drive device: flows hydraulic oil from the pump to the loading/unloading apparatus actuator when an operating tool is operated; flows the hydraulic oil from the pump to the steering actuator when a steering has become an operated state from a non-operated state regardless of an operation of the operating tool; and causes the hydraulic oil from the pump to be discharged to a tank via the relief valve to increase the torque of an engine when an increase instruction is inputted to the input unit and the steering is in a non-operated state. | 12-18-2014 |
| 20150040555 | HYDRAULIC DRIVE - In a hydraulic drive of a tool, a piston is adapted to be acted upon by a pump via a pressure limiting seat valve and a parallel switching seat valve of a valve arrangement. A restriction is provided in a pressure line upstream of the pressure limiting seat valve which is connected to a tank on the flow-off side. A drain line leads from a working chamber of the piston via the switching seat valve to the tank. A closing side is adapted to be acted upon by pressure and an opening side is adapted to be acted upon by a force generated when the pressure limiting seat valve responds. The pump is adapted to be switched off when the maximum operating pressure has been reached, so that the piston will execute a return stroke. A pressure-increasing restriction is provided on the flow-off side of the pressure limiting seat valve. | 02-12-2015 |
| 20150059331 | HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE AND CONTROL DEVICE THEREFOR - A hydraulic circuit for a construction machine including a direction control valve group including direction control valves provided in tandem to a center bypass passage, a bleed-off valve provided to the center bypass passage downstream of the direction control valve group, and a control valve controlling an amount of pressure oil to be supplied to the direction control valve. | 03-05-2015 |
| 20150068200 | HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE AND CONTROL DEVICE FOR SAME - A hydraulic circuit for a construction machine including a center bypass passage including a group of directional control valves arranged in tandem; and a bleed-off valve arranged in the center bypass passage on a downstream side of the group, wherein each directional control valve includes a first internal passage causing the pressurized oil supplied to the directional control valve to flow out to the center bypass passage and a second internal passage supplying the pressurized oil to a cylinder port, wherein a parallel passage is formed by the center bypass passage and the first internal passage by causing the pressurized oil discharged from the hydraulic pump to flow to the center bypass passage on the downstream of the directional control valve, wherein the second internal passage supplies the pressurized oil from the center bypass passage through an opening of a spool and/or the bypass passage to the cylinder port. | 03-12-2015 |
| 20150075151 | HYDRAULIC PRESSURE SUPPLY SYSTEM OF AUTOMATIC TRANSMISSION - A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump provided with first and second pump chambers formed therein to a high pressure portion and a low pressure portion of the automatic transmission through a high-pressure regulator valve, first and second switch valves, and a low-pressure regulator valve. | 03-19-2015 |
| 20150075152 | HYDRAULIC PRESSURE SUPPLY SYSTEM OF AUTOMATIC TRANSMISSION - A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump provided with first and second pump chambers formed therein to a high pressure portion and a low pressure portion of the automatic transmission through a high-pressure regulator valve, the switch valve, and a low-pressure regulator valve. | 03-19-2015 |
| 20150075153 | HYDRAULIC PRESSURE SUPPLY SYSTEM OF AUTOMATIC TRANSMISSION - A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump having two pump chambers to a low pressure portion and a high pressure portion and performs mode conversion from a full discharge mode to a two circuit mode or a half discharge mode according to variable control pressure of a solenoid valve. | 03-19-2015 |
| 20150075154 | HYDRAULIC PRESSURE SUPPLY SYSTEM OF AUTOMATIC TRANSMISSION - A hydraulic pressure supply system supplies hydraulic pressure generated at a hydraulic pump provided with first and second pump chambers formed therein to a high pressure portion and a low pressure portion of the automatic transmission through a high-pressure regulator valve, first and second switch valves, and a low-pressure regulator valve. | 03-19-2015 |
| 20150082784 | FLUSHING CIRCUIT FOR HYDRAULIC CYLINDER DRIVE CIRCUIT - The present invention provides a flushing circuit for a hydraulic cylinder drive circuit, by which the flushing of the circuit is conducted while protecting precision apparatuses of a control valve unit, because the flushing of a reciprocating hydraulic cylinder and its drive circuit is conducted while bypassing the control valve unit. | 03-26-2015 |
| 20150135701 | FLUID PUMP FOR A LINEAR ACTUATOR - A fluid pump for a linear actuator is provided. The pump causes a rod in the actuator to extend or retract by controlling the flow of fluid to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump includes a valve structure that enables the pump to redistribute fluid obtained from one portion of the fluid chamber on one side of the piston to the other portion of the fluid chamber on the other side of the piston without first returning the fluid to a fluid reservoir thereby increasing the efficiency of the pump. | 05-21-2015 |
